net: stmmac: fix enabling socfpga's ptp_ref_clock

There are 2 registers to write to enable a ptp ref clock coming from the
fpga.
One that enables the usage of the clock from the fpga for emac0 and emac1
as a ptp ref clock, and the other to allow signals from the fpga to reach
emac0 and emac1.
Currently, if the dwmac-socfpga has phymode set to PHY_INTERFACE_MODE_MII,
PHY_INTERFACE_MODE_GMII, or PHY_INTERFACE_MODE_SGMII, both registers will
be written and the ptp ref clock will be set as coming from the fpga.
Separate the 2 register writes to only enable signals from the fpga to
reach emac0 or emac1 when ptp ref clock is not coming from the fpga.
Signed-off-by: Julien Beraud <julien.beraud@orolia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c

@@ -291,16 +291,19 @@ static int socfpga_gen5_set_phy_mode(struct socfpga_dwmac *dwmac)
 	    phymode == PHY_INTERFACE_MODE_MII ||
 	    phymode == PHY_INTERFACE_MODE_GMII ||
 	    phymode == PHY_INTERFACE_MODE_SGMII) {
-		ctrl |= SYSMGR_EMACGRP_CTRL_PTP_REF_CLK_MASK << (reg_shift / 2);
 		regmap_read(sys_mgr_base_addr, SYSMGR_FPGAGRP_MODULE_REG,
 			    &module);
 		module |= (SYSMGR_FPGAGRP_MODULE_EMAC << (reg_shift / 2));
 		regmap_write(sys_mgr_base_addr, SYSMGR_FPGAGRP_MODULE_REG,
 			     module);
-	} else {
-		ctrl &= ~(SYSMGR_EMACGRP_CTRL_PTP_REF_CLK_MASK << (reg_shift / 2));
 	}
 
+	if (dwmac->f2h_ptp_ref_clk)
+		ctrl |= SYSMGR_EMACGRP_CTRL_PTP_REF_CLK_MASK << (reg_shift / 2);
+	else
+		ctrl &= ~(SYSMGR_EMACGRP_CTRL_PTP_REF_CLK_MASK <<
+			  (reg_shift / 2));
+
 	regmap_write(sys_mgr_base_addr, reg_offset, ctrl);
 
 	/* Deassert reset for the phy configuration to be sampled by